Grassy Fields Zone: Accidentally fall into a pit made by Eggman, and get teleported along with the water to his underground lab.
Frozen Pit Zone: Battle Eggman in snowy impact crater, but be careful not to fall into the freezing water!
Toxic Factory Zone: Battle Eggman in his chemical-producing factory, but try not to fall into the chemicals!
Final Fight Zone: Battle Brak Eggman on a floating platform in space! Watch out for the lava in the center!
Lava Mine Zone: Enter Eggman's secret mine, but be sure not to burn yourself!

This map pack is indeed interesting, because its not really often you see arenas made for bosses without an actual connection to the zone they're a part of, so lets go into what I think about the levels...

Grassy Fields: The entrance to the boss fight is really creative, I love how you accidentally meet the boss by falling from a platform into a cave, however there are some problems with this stage as a whole: No aesthetic. What I mean by this here is that while the boss stage has a sign of creativity, it absolutely lacks environment, a feeling you're in Grassy Fields Zone, no, grass textures don't count. I suggest placing flowers and bushes in places that make you feel like you're in a grassy field.

Frozen Goo: This one is my least favorite, and honestly it has to do with the boss design. Egg Slimer outside of his native stage is terrible to play with, and modifying the stage to a point where you can barely hit it just makes the boss fight more of a chore to beat, especially because he's flying faster than a player could catch him at. The environment just... it doesn't work dammit. Goop in a snow level, while it doesn't have to make sense, is really... anti-environmental in my opinion, if anything, that painful goop could be freezing ice, which makes better sense in a snowy atmosphere, because hot chemical water would melt the snow in the area away.

Lava Factory: This is my second least fight in this pack, its far too bland for my tastes and really, fixing the aesthetic would involve making the level too busy for it's own good, if you want to have a boss in a lava factory, make the arena feel like a factory, using pipes, steam jets, and even random Eggman crates would make the environment feel like you're battling Eggman in the warehouse of his factory or something.

Final Fight: This is by far the most intriguing boss fight of the pack by far, in fact, I say this is the best minimalistic boss fight with Brak Eggman I've ever seen. The walls of stage compliments the Line-of-sight attack Brak does, and the tiles help perfectly mark how you're supposed to battle the boss, the only issue that I have with the fight is that the space gravity is entirely non-existent, but at the same time, considering some of Brak's attacks, I can understand why it probably shouldn't have to be implemented.

I'll be honest here, I feel like this map pack had potential to at least plug in bosses outside of the vanilla bosses. If anything, the bosses that have been released should've gotten some spotlight, like FuriousFox's Green Hill Boss, or Shadow, or Knuckles, or even Egg Frostburn, two out of the 4 stages have creative gimmicks and ideas that would fit well in a level pack. But hopefully what you should get from this is that the aesthetic is the most important way to make your boss stages feel lively enough.

Well I must say Yoshi, you have quite a bit of potential in you. Mainly Lava Factory, I really like how you have to battle right above some lava, and the aesthetics of the map are quite nice. Certainly an improvement over v1.0. The other maps aren't as aesthetically pleasing, as they lack anything to break it up. Lava Factory is definitely the best map here, and if you followed what you did with that map and put it onto the other maps, they could be just as great.

Well I must say Yoshi, you have quite a bit of potential in you. Mainly Lava Factory, I really like how you have to battle right above some lava, and the aesthetics of the map are quite nice. Certainly an improvement over v1.0. The other maps aren't as aesthetically pleasing, as they lack anything to break it up. Lava Factory is definitely the best map here, and if you followed what you did with that map and put it onto the other maps, they could be just as great.

Wish you luck on your other maps Yoshi.

Thanks. The others will probably get better once they're actually updated. I'm currently thinking of ways to make Frozen Goo Zone better.

This is going to be my first time giving criticism to something, so here I go:

Grassy Fields: I don't know what to say about it. In 1.0, the cave was just a cube. But now, it is a cylinder.
It's... An improvement, I guess? The cave itself could use some more decoration, and it should be shrinked. Right now it is an huge cylinder. There's a lot of space to walk on.
You could even change the theme of the cave to a mine and make it more rocky?

Frozen Goo: The new textures you gave it clash with the theme, they look weird. Try going back with the ice blocks, it seemed to go along better with the snow.
Plus, it is truly annoying to have a really fast eggman that can switch directions in a dime, since by the time you get up on a block, the Eggman is already on the other side.
Maybe try giving the map a different boss, or make the axis for the boss smaller?

Lava Factory: So far, this is the best level in the entire pack!
In 1.0 it was just a cube with lava, but with the FOFs you gave it in this new update, it looks fantastic!
I don't think it would need more decoration, because it is looking good already!
A thing I would do would be darkening the entire map, and adding light blocks on the sectors where there is lava, so it gives the illusion that the lava is illuminating the map.

Final Fight: This is my least liked map in the entire pack.
I don't know where to start with it. So far, the map looks like a disk made of rock with metal borders floating in space. The sectors signaling what damages Eggman and where you can breath look weird when coloured, and even worse when you look at the entire map.
Maybe you can do something like Egg Rock Zone does, where there's a blue FOF that you can enter to breathe? I dunno what could you do for the other sectors that damage Eggman though. Maybe lasers, or a switch you can press that does something?
The corners that are used to block attacks have a weird texture, which kind of clashes with the map. I thought I saw a slime trail as soon as I entered the map, but it was the texture.
Try experimenting with different textures and shapes. Even lightning tricks!

In general, I think you should shrink the size of most maps. Currently, they are too big for a single boss (I'm not implying to add more bosses to the map, heh).

Overall, and I'm sure that more people think about this, you have incredible potential in map making. Please keep it up! You're doing great!

I have to say, you improved a lot from the last time. I'll go into details now:

Grassy Fields: Creative idea, I would recommend you making the outside area a bit smaller, or add some obstacles to reach the boss at least. Also make the teleport silent. Talking about the cave, still feels a bit flat. Since is a rocky cave consider playing with floor/ceiling levels to make it a bit irregular, and maybe add some water inside, since the entrance is underwater it would make sense.

Frozen Goo: It feels too similar to Lava Factory, but still you improved a lot on this one. You should try other boss here and see the results. Also try to add some details outside the factory so it doesn't look too blocky.

Lava Factory: This is your best work on the pack. I can't think of any improvement you can do here because the level is already great, but if you have any ideas don't be afraid to add them.

Final Fight: This is going well but still it needs a lot of work. you can try to add some details to the zones where you take oxygen (Maybe capsules?), The sectors where the boss loses his shield also could be rising and lowering lava fofs for example, not just red cubes. Maybe some obstacles to make the boss tricky would be neat too. If I were you i would experiment with death pits, like the old 2.0.x boss.

So far you're getting better at this. Keep up the good work.
If you feel more confident about your mapping skills I would encourage you to make more bosses. After all we're here to help you improve.
Don't lose your hopes on this! I see a lot of potential in you!

Wow, this hasn't been touched for three months. Just wanted to point out a couple things for those of you who use the music and haven't noticed: Y1 and Y2 use the same song although they aren't supposed to, and after I finish the newest version (2.0) it will no longer be a part the actual pack but can still be used, just with a few level title bugs. As for what's in the soon-to-be new version, Grassy Fields (Y1) has had some minor changes above ground and is completely different underground, Frozen Goo (Y2) is now Frozen Pit, and has been remade to use Eggscalibur, Lava Factory (Y3) is now Toxic Factory, with some texture changes and some slight changes to the structure, Final Fight (Y4) has been remade and is now smaller and you can now breath, and Lava Mine (Y5) has been remade above ground along with some texture changes, along with different textures underground with a small edit to the door. Only thing left to do is colormaps and Eggscalibur's cage. (Whenever I get an answer on my help thread for that...)